A fuel cell is a power generation system that converts chemical energy obtained from a reaction between oxygen and hydrogen in a hydrocarbon-based material such as methanol, ethanol, or natural gas, to electrical energy.
A fuel cell can be classified as a phosphoric acid type, a molten carbonate type, a solid oxide type, a polymer electrolyte type, or an alkaline type of fuel cell depending upon the kind of electrolyte used. Although each fuel cell operates in accordance with the same basic principles, the kind of fuel, the operating temperature, the catalyst, and the electrolyte are all dependent on the type of cell selected.
Recently, a polymer electrolyte membrane fuel cell (PEMFC), which has power characteristics superior to those of other fuel cells, an operating temperature that is lower, and starting and response characteristics that are quicker, has been developed. It has advantages in that it can be applied to a wide array of fields, such as a transportable electrical source for an automobile, for distributed power such as for houses and public buildings, and as a small electrical source for electronic devices.